The present invention relates to a method and device of relative positioning between agricultural machines and crops on their planting rows and more particularly to a method and device of active positioning of the agricultural machines elements, particularly for harvesting machines, next to the planting rows. More specifically, it is about a process and device of relative positioning between agricultural machines and crops on their planting rows, which favored application concerns the positioning of “stripping rotors” or similar harvesting elements used in many types of harvesters, mainly those of fruits.
As it is known, the attempt to position the active parts of the machines in the best position in relation to the points or area to be worked is obvious and consists of a continuous work of machine development teams. The efforts to achieve the control of the positioning between machine and planting row go from the static positioning at a given level or position to a dynamic following of a trajectory that is in accordance with a desired work area, in relation to the trees tops.
In this kind of activity there are many attempts in this direction, because generally the plants have their work targets: stem, branches, leaves and fruits, distributed in a more or less regular form for the same species and depending on the target to be reached, a more appropriate positioning can be vital for the better efficiency of the work or even its success.
Many ideas have already appeared, as well as equipment to assist in the positioning of active sets of harvesters, sprayers or other items of agricultural machines, and some items really became commercial products.
Some of such equipment are controlled by the operator, others are adjusted automatically through physical contact with the trees, even having counterweight or spring loaded systems as movement assistance.
Other ideas are also presented in such a way so as to have the active sets “copy” the trees during the service, on just one side or on both sides simultaneously, however how the devices would perform such activity is not indicated or specified.
The idea of positioning and/or displacing a device, whether harvest or any other type, to perform an agricultural task is already of public domain. In this sense, many patent applications are found, some of which became, as said, commercial products.
Amid the existent technology, one can mention that as defined on the U.S. Pat. No. 3,959,959, published in 1976, that claims the priority of French Patents FR19730039515 and FR19731107. The latter is a patent designed for the grape harvest by using two or more pairs of rotors, and in its claims the rotors of the same pair can get closer to or away from each other in order to better reach the goals of the harvest. Here, the normal position of the rotors is closer to the machine center, and the rotors move away because of the thrust received from the trees mass and in the absence of these forces, the return to the original position occurs through spring force. More specific details regarding this feature are not given.
Other solution known is that as defined in U.S. Pat. No. 4,173,859 of 13 Nov. 1979, derived from New Zealand Patent No. 179552, of 15 Dec. 1975, that foresees the rotors actuation in double pairs, now obligatorily, that also mentions in its claims “means of assembly that allow the rotors to move transversely”. In the patent one also does not claim the way how to obtain said effect.
One more solution is defined in U.S. Pat. No. 5,661,963, filed on 21 Apr. 1995, that generate the later filing in Brazil, on 16 Jan. 1996, under No. PI9604404-7, where in one claims a device to transform a fixed rotor in a copier rotor of trees tops in order to work them, and said device is fixed pivotally on the posterior corner of the bearer vehicle. Said bearer vehicle, when passing next to the trees rows, would allow the rotor to work the trees top in displacing from the back to the outside of the conveyor. A movement system, generated by spring load would tend to keep the rotor on the side and as far as possible from the bearer, in which occasion the rotor would reach the farthest branches. The thrust caused by the foliar mass would force the rotor back to the position on the conveyor rear when the conveyor is tangent to the trees. Thus, by action of these two opposite forces, the device allows the rotor to pass tangentially to the rows and work, sequentially, half of all perimeters of the trees set in planting rows.
There are other attempts to obtain the positioning of the stripping sets, such as that in U.S. Pat. No. 5,946,896, dated of 7 Sep. 1999, wherein four stripping sets fastened on common support mounted on a conveyor trailer, are controlled manually by an operator who, utilizing hydraulic means, positions said stripping sets on the working areas of the trees tops. The operator chooses the area to be worked and drives the stripping machine to this region; once this area is harvested, the same will be driven to another area and so on.
Now, treating more specifically the harvest processes, it is known that the fruits generally are not distributed on the trees tops in general uniformly; in most cases, their location is concentrated on the most external part of the top, where the insulation is more active. Thus, in the inner parts of the tops, a few or no fruits are found. On the other hand, the fruits are distributed around the whole top.
Normally the harvesters, while working, are displaced either over the trees or at the side of the trees rows, being tangent to the tops. The harvesting devices seek to work the tops and reach all places where the fruits are. In the event of stripping machines that use rods to strip fruits, the rods must have appropriate length in order to reach all top points that bear fruits. One of the inconveniences of these types of said harvesters, that work passing over the trees or displacing laterally to the tops, is the difficulty that both have to reach the region of tops that are placed between the trees, i.e., in the direction of the planting rows. This is the farthest region from the rotors, the points to which the vibratory rods are fastened.
The conventional way used to overcome this difficulty is to use longer rods and to work with the rotors as close of the tops side as possible. However, it occurs that the use of longer rods can be undesirable because they reach many times the sensible parts of trees and can still have their performance jeopardized due to their long length.